Rate of fire? No matter what the gun looks like, a semi-automatic weapon fires a round every time you pull the trigger. Automatic weapons are - for all intensive purposes - illegal. (see UPDATE at bottom)

Magazine capacity? Extra capacity magazines can be purchased for most semi-auto hunting rifles, and the reloading process on most normal capacity magazines is rather quick and easy anyway.

Appearance? The AR-15 has this scary black military design, while this Ruger looks less mean and threatening by virtue of its burnished wooden stock.

It seems that Jackson is promoting the "Mother's Day March to Halt the Assault" here in DC on May 9th. Not sure if I'll cover that one. My favorite line from Jackson?

We're the most violent country on Earth, and it doesn't have to be that way.

Sorry Jesse, but a quick Google will tell you that the honor belongs to South Africa, with 114.8 murders for each 100,000 people. The US has a murder rate of 6 per 100,000. By way of comparison, the gun-bereft Swedes have a rate of 10 murders per 100,000.

And contrast those numbers with the fact that at least a third of the Swiss own firearms, yet they have one of the lowest gun crime rates in the world.

Never let facts stand in the way of a good soundbite.

UPDATE: Instead of writing that automatic weapons are "illegal," I should have stuck with my original description: "highly regulated."

Fully automatic weapons have been restricted in the United States since the National Firearms Act of 1934, available only to police, military personnel, and private individuals who manage to obtain permission from the US Treasury Dept, pass an extensive background check, fully register the firearm and continually update the owner's address and location of the firearm and pay a $200 transfer tax. Some states require state permission as well. The US Treasury Dept. lists only a few hundred thousand lawfully owned fully automatic weaponss. The bulk of these are owned and used in the motion picture industry.

Possession of these types of firearms are Federally possible depending on additonal local or state laws, as explained by John of Argghhh in the comments section below.

The distinction between semi and fully automatic weapons is their ubiquity and how difficult they are to get; fully automatic weapons are essentially "nationally registered," something that many gun advocates fear as a first step to the eventual removal of second amendment rights. The crux of my argument remains, as legal ownership of fully auto weapons is not considered a factor in highly violent gun crime due to their careful regulation ...

Since 1934, only one legally owned machine gun has ever been used in crime, and that was a murder committed by a law enforcement officer (as opposed to a civilian).

... and "assault weapons" are often arbitrarily distinguished from regular semi-automatic firearms because of cosmetic purposes or slightly higher magazine capacities.

Point is, if I want to kill a bunch of people in a park, I can do it with the same tool that I'd use to go hunt deer.

(John can feel free to offer additional clarifications on that point)